Facebook wants to make the data its members enter into the social network’s profiles portable, so that they can move that data to other online services if they want, the company’s CEO said Wednesday.

It’s already possible to take some data out of Facebook for use in third party applications (but not store it), but extracting data and data objects (such as photos) would be a big step, and a bold one given the current dominance of Facebook, at least in the UK and in terms of speed of growth.

How they implement it is going to be very interesting, given the privacy concerns about the API. But if it does happen, and there are other sites that make use of it the way that application development within Facebook has taken off, it could be another huge leap forward in terms of making Facebook almost an integral part of the internet.